The present invention relates to pads for disk brakes and to disk brakes using the pads.
In general, in a disk brake, the braking action is produced by means such as, for example, cylinder and piston units which act on opposite surfaces of a rotating disk by means of pads.
As is known, a noise is often generated during this braking action and takes the form of a particularly annoying whistle which reduces travelling comfort.
The generation of noise of this type is attributed to vibratory phenomena which involve various components of the brake, also including the pads.
Much research has been carried out with the purpose of suggesting techniques for reducing or eliminating braking noise.
One of these techniques proposes that a weight be connected, by means of a elastic body, to a component of the disk brake which might start to vibrate. According to this technique, any vibration of this component of the brake is transmitted to the weight which, for low frequencies, oscillates in phase with the component to which it is connected. As the vibration frequency increases, the oscillations of the weight and of the brake component become increasingly out of phase until a condition of phase opposite is reached, in which the vibration of the component is reduced or cancelled out. Moreover, according to this technique, the weight may be fitted alternatively on the piston, on the caliper body, or on the pad.
This technique requires the entire structure of the brake to be designed specifically.
This designing is necessary in order to produce an intermediate elastic element suitable to be placed between the brake component the oscillations of which are to be damped and a suitable weight, and also to provide a seat in which the weight can oscillate, deforming the elastic body.
The need to modify the structure of the brake so greatly in order to reduce the whistle phenomenon represents a considerable disadvantage. In fact, given the complexity of the phenomena which occur during a braking operation, and given their dependence on the particular application, that is to say on the type of vehicle in which the disk brakes are used, a particular solution which is optimal on the basis of theoretical simulations may not be satisfactory as a result of experimental tests or as a result of its use for applications other than those provided for.
Arrangements which do not have a great impact on the overall structure of the disk brake are therefore of particular interest.